1347.] 



Advantages of Irrigation. 



153 



ADVANTAGES OF IRRIGATION. 

 The advantages of irrigation do not arise simply from the quan- 

 tity of water which they receive. The amount of saline matter 

 in the water, is an important consideration, and give some waters 

 an advantage over others. As an illustration of this statement, 

 which is confirmed, we copy the following analysis of water with 

 the remarks subjoined. The waters of New Yoik have already 

 received that attention which the importance of the subject de- 

 manded. 



The following are analyses of water from a well in the Boule- 

 vard St. Martin, and from the Seine, at Paris; by M. Lassaigne: 



Well, in Boulevard St. Martins. 



Supposing a bed of soil v.'ere watered from the well above men- 

 tioned, in quantity equal to the amount of rain which falls on an 

 average in the climate of London, that is about two inches deep 

 per month, or 12,465 gallons for each .square foot in a year; the 

 bed in the course of the year would receive, with the water, at 

 the rate of 3 tons, 15 cwt., 79 lbs., of sulphate of lime, per acre; 

 of carbonate of lime, 19 cwt., 53 lbs.; and of nitrate of magnesia, 

 and chloride of magnesium, 10 cwt., 74 lbs. The editors of the 

 Revue Horticole state, Avith reference to the preceding analysis, 

 that (he water of a well in the Jardin des Plantes, contains still 

 greater proportions of sulphate, and carbonate of lime, than that 

 of the one in the Boulevard St. Martin. 



